/Engine/Source/Runtime/SlateCore/Public/Application/SlateApplicationBase.h
Returns the window the provided widget is contained in
returns the window the provided widget is contained in or nullptr if it's not currently in a window
[TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [SWindow](API\Runtime\SlateCore\Widgets\SWindow) > FindWidgetWindow ( [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< const [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > InWidget ) const